CAREER: Coupling Geometry Acquisition and Digital Fabrication

3D扫描和数字制造技术正在迅速发展，它们的结合有可能极大地改变我们设计功能对象的方式，因为它们能够制造具有前所未有的几何复杂性的对象，同时大幅加快设计迭代。该项目的目标是为3D扫描和数字制造的紧密结合奠定算法基础，支持生命科学和医学的新应用。为此，研究将通过提出一种新的数据表示和专门设计的支持制造和扫描的新算法来改变传统的几何处理流水线。与难以处理海量和噪声数据集的传统全局优化方法不同，PI专注于健壮、易于并行化和内存占用小的半局部算法。这项研究将有两个主要推动力：为制造而扫描(ScanFab)和为扫描而制造(FabScan)。ScanFab管道将支持需要设计定制医疗设备和假体的医疗应用；为了验证其有效性，PI将与企业合作伙伴Sonova合作获取和重建耳道几何形状，并为设计下一代定制助听器提供交互技术。FabScan的推力将导致开发一种新的显微镜技术，用于估计细胞表面的2D和3D牵引力，这将是了解细胞发育过程中的迁移和癌症发生的基础；该技术将与国防部合作开发。苏黎世理工大学机械与工艺工程系，并将与米兰大学医学院合作进行一项大型生物学研究进行评估。开发的技术将被集成到PI的开源库中，使研究社区能够直接从这些贡献中受益。在ScanFab中，PI引入了一个集成的管道来获取、修改、模拟和制造现有3D对象的变体。该管道基于T网格，这是一种结合了粗糙和高度结构化的四边形网格的优点与三角形网格的效率和灵活性的几何表示。这项研究将解决：(1)点云到T网格的交互和核外转换；(2)在保证可制造性的同时对重建曲面进行交互编辑；(3)在制造之前使用有限元方法对新几何进行物理模拟，以研究其力学特性。在FabScan中，管道将被颠倒，以感知微观层面的力量。PI将制造出具有已知几何和物理性质的微结构，对其施加载荷，然后通过三维共聚焦显微镜获得变形的几何结构。通过求解有限元逆问题，结合初始几何和变形几何的知识，可以准确地重建牵引力。

3D scanning and digital fabrication technologies are rapidly evolving, and their combination has the potential to dramatically change the way we design functional objects by enabling the fabrication of objects with an unprecedented geometrical complexity while drastically speeding up the design iterations. The goal of this project is to lay the algorithmic foundation for tightly integrating 3D scanning and digital fabrication, to support new applications in life sciences and medicine. To this end, the research will transform the traditional geometry processing pipeline by proposing a new data representation and new algorithms specifically designed to support fabrication and scanning. In contrast to traditional global optimization methods, which struggle to deal with massive and noisy datasets, the PI focuses on semi-local algorithms that are robust, easy to parallelize and have a small memory footprint. The research will have two major thrusts: Scanning for Fabrication (ScanFab), and Fabrication for Scanning (FabScan). The ScanFab pipeline will support medical applications that require the design of customized medical devices and prostheses; to validate its effectiveness, the PI will collaborate with corporate partner Sonova to acquire and reconstruct the geometry of the ear canal, and to provide interactive techniques for designing the next generation of customized hearing aids. The FabScan thrust will lead to the development of a novel microscopy technique for estimating 2D and 3D traction forces on the surface of cells, which will be fundamental to understanding cell migration in development and cancer genesis; the technique will be developed in collaboration with the Dept. of Mechanical and Process Engineering at ETH Zurich, and will be evaluated in a large biological study in collaboration with the medical school in the University of Milano. The developed techniques will be integrated into the PI's open-source library, to allow the research community to directly benefit from these contributions.In ScanFab, the PI introduces an integrated pipeline to acquire, modify, simulate, and fabricate a variant of an existing 3D object. The pipeline is based on T-meshes, a geometrical representation that combines the benefits of coarse and highly structured quadrilateral meshes with the efficiency and flexibility of triangle meshes. The research will tackle: (1) the interactive and out-of-core conversion of point clouds to T-meshes; (2) the interactive editing of the reconstructed surfaces while ensuring fabricability; (3) the physical simulation of the new geometry to study its mechanical properties before fabrication, using a Finite Element Method (FEM). In FabScan, the pipeline will be reversed to sense forces at the microscopic level. The PI will fabricate a microstructure with a known geometry and physical properties, apply loads to it, and then acquire the deformed geometry via 3D confocal microscopy. The traction forces will be accurately reconstructed by solving an inverse FEM problem, combining the knowledge of the initial and of the deformed geometry.